JPS62148292A - Image-receiving sheet for thermal transfer recording - Google Patents

Abstract

PURPOSE:To provide an image-receiving sheet having an image-receiving layer with favorable adhesion, by incorporating an aqueous emulsion of a cationic acrylic copolymer, an amino compound having two or more amino groups in one molecule thereof and an epoxy compound in a specified ratio into an image- receiving layer. CONSTITUTION:A base is a polyolefin synthetic paper having a brightness of not less than 90% and a Bekk index of not less than 1,000sec. The base has, for example, a multilayer structure of a base layer A, a paper form layer B comprising 8-65wt% of an inorganic fine powder and a surface layer C comprising up to 3% of an inorganic fine powder having an average particle diameter of not more than 1mum. The base layer A is constituted of a biaxially stretched film comprising 0-45wt% of an inorganic fine powder. An aqueous dispersed liquid comprising 1-2pts.wt. of an amino compound having two or more amino groups in one molecule thereof and 2-50pts.wt. of an epoxy compound per 100pts.wt. of an aqueous emulsion of a cationic acrylic copolymer is used as a material for forming an image-receiving layer.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an image receiving sheet for thermal transfer recording, particularly a color hard disk used in a video printer, etc., which forms characters and images on a receptor using electrical signals from a thermal head, etc. Regarding copying.

[Prior art]

Conventionally, a transfer sheet having a transfer layer containing a heat-melting coloring material containing a pigment or a sublimable or vaporizable dye is superimposed on a receiving sheet, and the transfer sheet is heated to transfer the pigment or dye contained in the transfer layer. Thermal transfer is known in which a pigment image or a dye image is formed on a receiving sheet by thermally melting, sublimating, or vaporizing the pigment and transferring it to a receiving sheet.

Specifically, in a transfer type thermal recording method using a heat source controlled by an electric signal such as a thermal head, as shown in FIG. A receiving sheet 1 having a layer 11 and a support 12 is transferred to a drum 3.
and a heat source 4, and a color hard copy is obtained by transferring the color material of the layer 22 onto the image receiving/customer layer 11 in response to an electric signal.

The image receiving layer 11 differs depending on the content of the coloring material used, and in the case of a sublimable basic dye type coloring material, activated clay (activated clay) is used.
In the case of a sublimable disperse dye type coloring material, the layer is composed of a layer of a polymeric material such as polyester. In conventional receptors, the image receiving layer 110 is uneven due to uneven thickness of the support or surface irregularities.
The surface has irregularities of 5 to 15 μffi, and 11!
There was undulation of 10 to 20 μm per No. 11. Even when surface treatment using a supercalender is used, there is a limit to the level of unevenness or waviness, which can only be improved to some extent. Therefore, the coloring material transferred from the coloring material layer 22 is transferred to the image receiving layer 11.
The surface unevenness is 3 to 5 μm or more or the waviness is 1 per 1 mm.
If the diameter is 0 μm or more, not only heat-melting coloring materials but also sublimation coloring materials will not be transferred accurately in accordance with the image signal, causing disturbances in image quality such as missing or missing dots, and giving a grainy feel to midtones. (Japanese Patent Application Laid-Open No. 59-214696).

In addition, as the support 12, paper or inorganic fine powder can be used for
Synthetic paper made of stretched film of thermoplastic resin containing 50% by weight (Japanese Patent Publication No. 46-40794), transparent polyethylene terephthalate film, or transparent film with silica or calcium carbonate on the surface to improve whiteness and ink receptivity. Coated synthetic paper, etc., whose surface is coated with an inorganic compound such as, together with a binder, is used.

[Problems with conventional technology]

Considering the after-use of the thermally transferred receiving sheet (copying, pencil writing, storage stability, etc.), synthetic paper and plastic film are recommended as the image receiving sheet for thermal transfer recording in terms of strength, dimensional stability, and dust-free property. is preferred.

However, although transparent plastic films have excellent copyability, they have low whiteness, lack hiding properties, and have weak image contrast, making them difficult to decipher.

Therefore, synthetic paper containing inorganic fine powder with a high whiteness of 90% or more or coated synthetic paper with an ink-receiving layer provided on the surface of a transparent film is preferred.

However, the latter coated synthetic paper has a whiteness level (at least 85%, preferably 90%) that provides good image contrast.
In order to obtain the above), it is necessary to apply a large amount of coating agent, which is not only economically disadvantageous, but also causes the coating receiving layer to trap on the transfer paper side during thermal transfer, or to There is a problem that the coating layer falls off during use and becomes a source of dust. Another drawback is that even if you try to write the contents of the image with a pencil on the back side of the film, you cannot do so.

The former synthetic paper made of a stretched thermoplastic resin film containing fine inorganic powder is excellent as an image-receiving sheet support for thermal transfer recording in terms of pencil writability, water resistance, and dust-free property.

[Problem that the invention seeks to solve]

The synthetic paper made of this stretched film has a structure in which the core is inorganic fine powder, fine voids are formed around the powder by stretching, and the powder protrudes from the surface.

The image thermally transferred to the part of the inorganic fine powder that protrudes from the surface is pulled by the transfer body 2 and falls off from the surface of the receiving sheet l, resulting in image chipping (white spots).
There are many problems that tend to occur.

Therefore, the surface of this synthetic paper is coated with a thermoplastic resin film that does not substantially contain inorganic fine powder, especially a nonpolar polyolefin film such as polypropylene or polyethylene that has excellent chemical resistance (Japanese Patent Application No. 59-1248
No. 82) may be used.

However, since the polyolefin of this film material does not have a polar group, it has poor adhesion to the aqueous image-receiving layer.

That is, commonly used image-receiving layers include resins that exhibit good adhesion to heat-melting coloring materials containing pigments, resins that exhibit dyeability to rubber, wax, and sublimable or vaporizable dyes; Rubber, wax, or a mixture of these and an organic or inorganic filler is used.

Such resins, rubbers, waxes, etc. are coated with blade coaters, -
r-'y-+4 The image-receiving layer is formed by coating and drying on a support using a normal coating machine such as a fucoater, roll coater, or percoater, or a size press or a gate roll device. It is usually used after being dissolved. However, from the viewpoint of safety in the coating process (fire, organic container poisoning, etc.), it is strongly desired to use a water-soluble or water-dispersed coating type image-receiving layer forming material.

When synthetic paper coated with a polyolefin film is used as the support 12, when an image-receiving layer is provided on the support using a water-soluble or water-dispersed resin (emulsion, dispersion, etc.), the support and the image-receiving layer has poor adhesion, and a reverse trapping phenomenon occurs in which the image-receiving layer 11 is transferred to the second surface of the transfer body during transfer.

The present invention uses a water-based image-receiving layer-forming material on a highly smooth polyolefin synthetic paper, which is considered to be the most preferable image-receiving sheet support in terms of physical properties such as chemical resistance and economic efficiency, to achieve adhesion. The present invention provides an image-receiving sheet having a good image-receiving layer.

[Specific measures to solve the problem]

In the present invention, a synthetic paper made of a polyolefin film with a whiteness of 90% or more is used as a support, and the surface of this support is
．． In an image-receiving sheet for thermal transfer recording provided with an image-receiving layer having a wall thickness of 5 to 20 microns, the image-receiving layer contains (A) a cationic acrylic copolymer emulsion (B)) 2 in one molecule. Amine-based compound (C) having at least three amino acid mmσ groups; an epoxy compound containing the above components (6) and 0; Provided is an image-receiving sheet for thermal transfer recording, which is obtained by spreading a resin composition containing 2 to 50 parts by weight of a zero component on a support and drying the resin composition. It is something to do.

(Support) The support is a polyolefin synthetic paper with a whiteness of 90% or more, for example: (1) A paper-like layer is a polyolefin resin film containing 8 to 65 vd% of inorganic fine powder, and the surface is coated with an inorganic Synthetic paper with a Beck index of 1,000 seconds or more and a multilayer structure with a polyolefin resin film as a surface layer that does not contain fine powder or contains 3% or less of inorganic fine powder with an average particle size of 1 micron or less ( Patent application No. 59-124882
No.-).

■ A biaxially stretched polyolefin resin film containing 0 to 45 wt% of inorganic fine powder is used as a base layer, and a paper-like polyolefin-axially stretched film containing 8 to 65 wt% of inorganic fine powder is formed on the surface of this base layer. A synthetic paper with a multi-layer structure (Japanese Patent Publication No. 46-40794) or a paper-like layer of this synthetic paper is compressed with a mirror roll to obtain a Peck index of 1.00.
0 to 5,000 seconds, preferably 3,000 seconds or more.

As the polyolefin, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, poly(A-methylpentene-1), polystyrene, etc. can be used.

The fine inorganic powders to be added to the polyolefin include calcium carbonate, calcined clay, diatomaceous earth, Merck, titanium oxide, barium sulfate, aluminum sulfate, silica, etc. with an average particle size of 10 microns or less for the paper layer. Illustrated.

In particular, particles having an average particle size of 3 microns or less are preferred because the protrusion height can be reduced.

Titanium oxide, barium sulfate, aluminum sulfate, silica, and the like can be used as the inorganic fine powder having an average particle size of 1 micron or less, which may be added to the surface layer if necessary.

The support (2) of the present invention can contain other layers in addition to the surface layer and the paper-like layer. The synthetic paper (2), which is a preferred support, has a base layer made of a biaxially stretched film of the composition (A) below, and a uniaxially stretched film of the composition (e) below on the front and back surfaces of this base layer. This is a synthetic paper (see Fig. 2) having a structure in which a uniaxially stretched film of the surface layer of the following odor composition is laminated on both sides or one side of the paper-like layer via a paper-like layer.

・Container base material layer composition (a), polypropylene 50-95% by weight (b)
, 0-30% by weight of a resin selected from high-density polyethylene, medium-density polyethylene, low-density polyethylene, and ethylene/IMJ vinyl copolymer (C), 50-5% by weight of inorganic fine powder (B)
Paper-like layer composition (a), polypropylene 35-92% by weight (b
), resin selected from polystyrene, high density polyethylene, medium density polyethylene, low density polyethylene, ethylene/vinyl acetate copolymer 0-30% by weight (C), inorganic fine powder 8-65% by weight (
C) Surface layer composition Polypropylene containing 0 to 3% by weight of inorganic fine powder.

If a part of the polypropylene (50% by weight or less) is replaced with polystyrene or polyethylene, the gloss of the surface layer can be reduced.

This synthetic paper is a uniaxially oriented film (A) obtained by extruding the base layer composition of (A) into a sheet shape and stretching it in one direction at a temperature lower than the melting point of polypropylene.
A melt laminated film of co-extruded compositions (B) and (C) is laminated on both sides of the polypropylene so that the paper-like layer composition (B) is in contact with the film (2), and then this laminated film is It is a synthetic paper obtained by stretching in a direction perpendicular to the stretching direction at a higher temperature and temperature. Further, a molten film of the coextruded compositions (B) and (C) is laminated on one side of the film (A) uniaxially oriented in the longitudinal direction so that the composition (B) is in contact with the film (A), Composition [F]) on the other side of the film (A)
It may also be a multi-layer synthetic paper obtained by transversely stretching a laminate obtained by extruding a molten film of the above using a separate extruder. If the base material layer contains inorganic fine powder,
A large number of fine pores can be created inside the film of the base layer.

The base layer (A) of the stretched synthetic paper film contributes to increasing the strength of the synthetic paper. In addition, paper-like layer film (B,
B) exhibits a paper-like texture. This paper-like layer (B) shades the base material layer and gives the synthetic paper a paper-like feel.

The surface layer 0 is covered with a paper-like layer containing inorganic powder.
In summer, it prevents the inorganic fine powder from falling off from the synthetic paper, and the width of the convex part that is isolated and protrudes from the surface (Figure 3≠)
Compared to the case where no surface layer is provided (see FIG. 4), white spots do not occur and the height (h) in FIG. 3 can be reduced to a level that does not cause any problems in practice.

However, the components other than the matrix polypropylene (a) in each layer play the following roles.

Base layer (2) (b), low density polyethylene, medium density polyethylene, high density polyethylene, ethylene/vinyl acetate copolymer: facilitates stretching of synthetic paper. Strengthens the adhesion with the paper layer.

(C), Inorganic fine powder: A large number of fine pores are created inside the base layer film by stretching to form a synthetic paper. Make the base material layer opaque. Makes stretching easier.

The upper limit of the inorganic fine powder (C) in the base layer is 50% by weight. As the amount of inorganic fine powder increases, the number of pores inside the film increases, and although synthetic paper can be made lighter and more opaque over a wide range, its tensile strength decreases. Further, polyethylene (b) contributes to improving stretchability and impact resistance, but excessive addition leads to a decrease in the bending strength of the synthetic paper, so the upper limit should be 30% by weight or less. A preferred composition of the base material layer is as follows.

(a), polypropylene 60-85% by weight (b)
, 0 to 8% by weight of resin such as the aforementioned polyethylene (C), inorganic fine powder 15 to 40% by weight paper-like layer CB) (b), polystyrene, high density polyethylene, medium density polyethylene, low density polyethylene, ethylene/acetic acid Vinyl copolymer: Improves stretchability. Furthermore, polystyrene and high-density polyethylene improve the foldability of synthetic paper.

(C), inorganic fine powder: For opacity, whitening, and paper-like formation of paper-like layers Contribute.

In order to increase the opacity of the synthetic paper, the content of the inorganic fine powder in the paper-like layer is 8% by weight or more. However, since mechanical strength (compressive strength, tensile strength, etc.) as a paper-like layer is required, the upper limit of the inorganic fine powder should be 65% by weight. (
Resin such as polyethylene (b) contributes to improving the stretchability and foldability of synthetic paper, but its effect on the adhesive layer of the uniaxially stretched film is insufficient to the extent that it contributes to the biaxially stretched film of the base layer. Since it is small, there is no need to actively mix it.

τ°1 The preferred composition of the paper-like layer is as follows.

(a), polypropylene 45-65% by weight (b
), resin such as polyethylene 0-5% by weight (C), inorganic fine powder 35-55% heavy needles surface layer 0 (C), inorganic fine powder: improves whiteness, reduces gloss and smoothness, improves transfer image Improves color rendering properties.

Next, the thickness of each layer will be described.

The thickness of the multilayer support is 40 to 800 microns, preferably 60 to 300 microns. The base layer (A) is
It accounts for over 40% of the thickness of synthetic paper.

The wall thickness of the surface layer C) is between 3 and 15 microns. If it is less than 3 Bacron, the inorganic fine powder protruding from the surface of the paper-like layer (6) will also protrude from this surface layer C), and no effect of preventing white spots can be expected. The particle size of the inorganic fine powder of the paper-like layer (B) is usually 3 microns or less, preferably 0.1 to 2 microns. In addition, if the thickness of the surface layer C) exceeds 15 μm, the roughening effect of the paper-like layer (B) and the appearance of the paper-like layer (C)
The surface layer is highly glossy, making the image glare and difficult to see, and the smoothness not only makes it difficult to write with a pencil, but also causes poor peeling between the transfer sheet and the image-receiving sheet. This may cause the image to become unclear due to chipping, punching, etc.

The thickness of the paper-like layer (B) is such that the support 12 has sufficient whiteness (9
0% or more), it is usually 5 to 200 Bacron, and when the support is provided with a base layer (A), it is usually 5 to 60 Bacron.
It is micron.

Projections 14 from the surface 13 of the surface layer (C) of the support 12
As shown in Figure 3, those whose major axis t is 50 microns or more are 0. IW? It is important that there be no more than 10 pieces per chip, since chipping of the thermally transferred image does not pose a practical problem.

Even if the average particle size of the inorganic fine powder is 10 microns or less, there may be a small amount of particles with a particle size of 15 microns or 20 microns, or there may be particles that aggregate together and have a major axis of 50 microns. There are things that are as large as microns. If these giant particles exist on the surface of the support 12 of the image-receiving sheet 1, the image-receiving layer 11 provided thereon will not be able to form a uniform film, and in severe cases will form pinholes, which will cause white spots. .

The height h of the protrusions protruding from the flat surface of the resin surface 13 of the surface layer 0 of the support 12 is smaller than the major axis t of the inorganic fine particles. This protrusion with a height h of 20 microns or more is 0.
From the viewpoint of preventing white spots, it is preferable that the number is 5 or less per 1 m'.

Therefore, in the case of the synthetic paper (2), the surface is smoothed by applying pressure with a mirror roll to reduce the height of the protrusions.

[Image receiving layer]

As the image-receiving layer forming material, an aqueous dispersion containing a resin exhibiting dyeability with sublimable or vaporizable dyes or a mixture of these and organic or inorganic fillers is used.

Specifically, (A) cationic acrylic copolymer aqueous emulsion; ■) amino-based compound having two or more amino groups in one molecule; Component (B) is 1 to 20 parts by weight based on 100 parts by weight of resin solid content of component (2).
An aqueous dispersion in which component (C) is blended in an amount of 2 to 50 parts by weight, or a filler further blended with this aqueous dispersion is used.

An example of the aqueous cationic acrylic copolymer emulsion of component (A) is: ■ A cationic monomer represented by the general formula (a) or (b), io, s ~ 10 mol%, and a vinyl monomer of the pond. Body 99.5~
It is an emulsion obtained by emulsion polymerization of 90 mol% of copolymers, and the glass transition temperature of this copolymer is 110°C to +80°C. Carbon number 2
-4 alkylene group, and R3 and R4 are H or an alkyl group having 1 to 4 carbon atoms. ] Examples of compounds in (g) include dimethylaminoethyl methacrylate, diethylamine ethyl methacrylate, -diptylaminoethyl acrylate, etc.; examples of compounds in (g)) include dimethylaminoethyl acrylamide, dimethylaminoethyl acrylamide, dimethylamine ethyl methacrylamide, etc. etc.

Other vinyl monomers include styrene, methyl methacrylate, ethyl acrylate, n-butyl acrylate, tert-butyl acrylate, ethyl methacrylate, vinyl chloride, ethylene, acrylic acid, methacrylic acid, itaconic acid, acrylonitrile, Examples include methacrylamide.

■Next (C) ~ (Cationic monomer (c) indicated by a mountain)
Cd) An aqueous emulsion (emulsion) of a copolymer of [in the formula, the definitions of R', R", and R4 are the same as in (a)] and other vinyl monomers, and a copolymer of The polymer has a glass transition point of 110°C to +80°C.

As other monomers, those described in (■) can be used.

Emulsion polymerization itself is well known to those skilled in the art. As surfactants used in the emulsion polymerization, anionic, cationic, amphoteric, and nonionic surfactants can be used alone or in combination of two or more.

Examples of the binder include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, sorbitan alkyl ester, and polyoxyethylene sorbitan alkyl ester. Examples of cationic surfactants include dodecyltrimethylammonium chloride, stearyltrimethylammonium chloride, and N-2-ethylhexylpyridinium chloride. 51!1 layer ΩTunkai The most preferred is a nonionic surfactant. Among them, polyoxyethylene alkylphenyl ether is particularly preferable.

The surfactant is used in an amount of 1 to 5% by weight based on the total amount of monomers.

Furthermore, a water-soluble polymer such as gelatin or polyvinyl alcohol may be used in combination as a protective colloid.

In addition, as a radical polymerization initiator in emulsion polymerization,
Redox L 24'-azobis-(2-amidinopropane) dihydrochloride, azobiscyanovaleric acid) IJium salt, peroxide Hydrogen can be used for the housing, but 2,2'-azobis(2
-amidinopropane) dihydrochloride is most preferred.

The polymerization initiator is 0.01 to 0.5 weight 7o of the total amount of monomers.
Use at a ratio of

If the glass transition point of the copolymer of the emulsion as the prison component is less than 110° C., the resulting film will become sticky and cause blocking. On the other hand, if the temperature exceeds +80°C, it is difficult to form a film and the adhesion to the support is poor.

(Amino compounds) (3) As for the amino compounds of the component, polyalkylene polyamines such as diethylene triamine and triethylene tetramine; epichlorohydrin adducts of polyethylene imine, ethylene urea, and polyamine polyamides [products include -Dick Bercules] Company Kaimen-557
H, AF-100 of Arayo Forestry Chemical Industry ■), aromatic glycidyl ether or ester adduct of polyamine polyamide, etc. (trade name: Sanmide 352 of Sancho Kagaku ■)
．． 351, X-2300-75, available from Shell Chemical (Keg Ebicure 3255).

(Epoxy compound) (As the epoxy compound of the O component, bisphenol A
Diglycidyl ether of bisphenol F, diglycidyl phthalate, polypropylene glycol diglycidyl ether, trimethylolpropane tricidyl ether, etc. can be used.

When this epoxy compound is emulsified and dispersed in water using an emulsifier or a protective colloid, it can be easily mixed with the aqueous cationic acrylic copolymer emulsion as a carrier component.

(Filler) As the inorganic filler, synthetic silica such as white carbon with an average particle size of 0.5 microns or less, inorganic pigments such as clay, talc, aluminum sulfate, titanium dioxide, zinc oxide, etc. can be used, preferably an average particle size of 0.5 microns or less. Synthetic silica such as white carbon of 0.1 μm or less, and inorganic pigments such as light or heavy calcium carbonate can be used.

Various fine polymer particles can be used as the organic filler, but the particle diameter is preferably 10 μm or less.

Examples of polymers constituting the organic filler include methylcellulose, ethylcellulose, polystyrene, polyurethane, urea/formalin resin, melamine resin, phenol resin, iso(or diiso)butylene/maleic anhydride copolymer, styrene/maleic anhydride. acid copolymer,
Polyvinyl acetate, polyvinyl chloride, vinyl chloride/vinyl acetate copolymer, polyester, polyacrylic ester, polymethacrylic ester, styrene/butadiene/
Examples include acrylic copolymers.

These fillers are usually used in an amount of 30% by weight or less. In particular, inorganic fillers can be treated with nonionic, cationic, or amphoteric activators such as funnel oil, sodium dodecyl sulfate, organic amines, and sodium metal soap lignin sulfonate, so that they can be used for papermaking and transfer paper 2 ink. It has improved wetting and can be used conveniently.

(Composition) (A), (The blending ratio of the sand and 0 components is 1 to 20 parts by weight of the [F]) component to 100 parts by weight of the resin solid content of the emulsion of the (A) component, (C) The ingredients are 2 to 50 parts by weight.

This coating receiving layer consists of component (A), component C), component (■) and Ω.
It forms a film by performing a crosslinking reaction with the components, and if the above conditions are exceeded, the adhesion between the support and the receptor layer will be poor.

(Reception/-) The image-receiving layer 11 is formed by coating and drying the surface layer Ω side of the support 12. For coating, play)”:ff-
1,! A common coating machine such as a 7-s()-x-ta, roll coater, per coater, size press, gate roll device, etc. is used.

The thickness of the image-receiving layer 11 is between 0.5 and 20 microns, preferably between 3 and 15 microns. After coating and drying, in order to impart smoothness to the image-receiving sheet, it may be compressed using supercardan to adjust the smoothness of the sheet.

Example 1 of fabricating a support (1) 16% of carunium carbonate with an average particle size of 1.5 is blended into a mixture of 79% by weight of polypropylene with a melt index (MI) of 0.8 and 5% by weight of high-density polyethylene. (A) was mixed in an extruder set at 270°C, extruded into a sheet, and cooled in a cooling device to obtain a non-stretched sheet. After heating this sheet to 140℃,
It was stretched 5 times in the machine direction.

(2) polypropylene (C) with MI4.0;
Composition (8), which is a mixture of 55% by weight of polypropylene with 0.0% polypropylene and 45% by weight of calcium carbonate with an average particle size of 1.5μ, is melt-kneaded in a separate extruder, laminated in a die, and coextruded to produce a sheet ( Laminate C) on one side of the 5-times stretched sheet of 1) with C) on the outside, and on the opposite side of the 5-times stretched sheet of (1), 55% by weight polypropylene with an M I of 4.0 and an average particle size of 1.5μ. Composition (2), which is a mixture of 45% carbonic acid, is melt-kneaded in another extruder, extrusion laminated, and then 60%
℃, heated to 162℃, stretched 7.5 times in the transverse direction with a tenter, annealed at 165℃,
Cool to 0℃, slit the ears and make 4 layers (C/B/A).
/B; wall thickness 10/30/70/35 microns) grooved synthetic paper was obtained.

The Beck index of surface C of this synthetic paper was 6,800 seconds, and the whiteness as a support was 95.6%.

In addition, the number of protrusions with a long diameter t of 50 microns or more that protrudes from the resin surface 13 of the surface layer C is 4 per 0.1 m', and those with a height of 20 microns or more are 0.1 m.
'There was one per piece.

Example 2 (16% by weight of calcium carbonate with an average particle size of 1.5 microns in a mixture of 79% by weight of polypropylene with a melt index (MI) of 0.8 and 5% by weight of high density polyethylene)
The mixture was mixed and kneaded in an extruder set at 270°C, extruded into a sheet, and cooled in a cooling device to obtain a non-stretched sheet. This sheet was heated to 140°C and then stretched 5 times in the machine direction.

(21M I 4.0 f/10 min polypropylene 9
7.5% by weight of barium sulfate 2.5% with an average particle size of 0.3μ
Composition C) mixed with 55% by weight of polypropylene with MI 4.0 and calcium carbonate 4 with an average particle size of 1.5μ
Composition (8) mixed with 5% by weight was melt-kneaded in a separate extruder, laminated in a gou, and coextruded to form a sheet (1).
MI 4.0 was laminated on one side of the 5x stretched sheet of (1) with (C) facing outward, and on the opposite side of the 5x stretched sheet of (1).
Composition (B), which is a mixture of 55% by weight of polypropylene and 45% by weight of calcium carbonate with an average particle size of 1.5μ, was melt-kneaded in a separate extruder, extrusion laminated, cooled to 60°C, and then heated to 162°C. It was heated, stretched 7.5 times in the transverse direction with a tenter, annealed at 165°C, cooled to 60°C, and the edges were slit to form 4 layers (C/B/A/B; wall thickness 10/30). /70/35 micron) structure was obtained.

The Peck index of surface C of this synthetic paper was 5.700 seconds, and the whiteness as a support was 96.0%.

In addition, the number of protrusions with a long axis of 50 microns or more that protrudes from the resin surface 13 of the surface layer C is 97 per 0.1 m2, and the number of protrusions with a height of 20 microns or more is 0.1
There were 2 pieces per m'.

Example 3 As the composition of the surface layer (C), instead of polypropylene with an MI of 4.0, 98% by weight of polypropylene and an average particle size of 0
．． A synthetic paper having the physical properties shown in Table 1 was obtained in the same manner as in Example 1 except that a mixture of 25 micron TiO and 22% by weight of TiO was used.

Example 4 (1) 16% by weight of calcium carbonate with an average particle size of 1.5 microns in a mixture of 79% by weight of polypropylene with a melt index (MI) of 0.8 and 5% by weight of high-density polyethylene.
(2) was mixed in an extruder set at 270°C, extruded into a sheet, and cooled with a cooling device to obtain a non-stretched sheet. This sheet was heated to 140°C and then stretched 5 times in the machine direction.

f2) 45% by weight of calcium carbonate with average mtlt, s microns in 55% by weight of polypropylene with MI 4.0
The composition (B) mixed with the above was melt-kneaded in an extruder, extruded into a sheet from a die, laminated on both sides of the 5@stretched sheet of (1), then cooled to 60°C, heated to 162°C, After stretching 7.5 times in the transverse direction with a tenter and annealing at 165°C, cooling to 60°C and slitting the edges, a three-layer structure (B/A/B; wall thickness 35/70/3) was obtained.
5 micron) synthetic paper was obtained.

Note that the number of protrusions was measured by the following method.

(1) Shine an oblique light onto the surface of a synthetic paper sample cut to 20m x 25c1n, visually locate and mark the protruding parts.

(2) Observe the marked protrusions with a stereomicroscope set to 25x magnification, measure with the &2 scale of a PEAK scale loupe, and count the number of protrusions with a major axis of 50 μm or more.

(3) Do this for two samples, and let the total number be the number of protrusions (diameter) per 0.1 m2.

(A) All of these protrusions were measured using a three-dimensional roughness analyzer Model SPA-11 (product name) manufactured by Koita Research Institute, and those with a height of 20μ or more were determined to be 0.1 m”.The number of protrusions in this paper (
high).

(Example of making an aqueous emulsion of a cationic acrylic copolymer) Example 1 Into a separable flask equipped with a stirrer, a condenser, and a thermometer, ioo parts by weight of ion-exchanged water purged with nitrogen was added, and then polyester as a surfactant was added. Two parts by weight of oxyethylene nonylphenyl ether were added and dissolved.

Next, this surfactant solution was kept at 75°C, and 2 parts by weight of dimethylaminoethyl methacrylate was added as a cationic monomer, and then 36% hydrochloric acid was diluted with ion-exchanged water to a hydrochloric acid concentration of 18%. , 6 parts by weight and thoroughly mixed to neutralize the cationic monomer, then add 2.2 parts by weight.
0.7 parts by weight of a 14% aqueous solution of '-azobis(2-amidinopropane) was added. Then 1/1 of methyl methacrylate and 2-ethyl-hexyl-acrylate
(Weight ratio) Continuous dropping of 98 parts by weight of the mixed solution was started.

The inside of the flask is kept at 78℃±2℃ by water bath.
The dropwise addition of the 7-mer mixture was completed in 4 hours.

After the completion of dropping the seven-mer mixture, 212'-azobis(2-
1 t-0.7 parts by weight of a 14% aqueous solution of (amidinopropane) was added thereto, the temperature inside the flask was set at 82±2°C, and the flask was allowed to stand for 2 hours, and then cooled to obtain a cationic emulsion.

The resin concentration of the obtained emulsion was measured by the method shown below and was found to be 50%.

Method for measuring O resin concentration (according to JIS K-6833) Sample 11 was accurately weighed on an aluminum plate with a diameter of 4 m, placed in a dryer kept at 105 to 110°C, heated for 3 hours, and then dried in a desiccator. After cooling, the dry weight of the sample was accurately weighed.

Example 1 A coating agent having the following composition was applied to the surface layer C) side of the synthetic paper support obtained in Example 1 so that the solid content was approximately 12/cm.
℃ for 30 seconds to form an image-receiving layer (thickness approx.
An image-receiving sheet provided with microns) was obtained.

(A) Cationic acrylic copolymer emulsion obtained in Production Example 1 (solid content 50%) 200 parts by weight Q3) Polyethyleneimine [Epomin 5P-018 (trade name) manufactured by Nippon Shokubai Chemical Co., Ltd.] 66 parts by weight A water-dispersed emulsion of diglycidyl ether of bisphenol A [1 Epikote 828'' (trade name, epoxy equivalent: 187) of Chemical Shell Epoxy Chemical ■) (solid content 60% by weight) Instead of the synthetic paper of Example 1 as a support Next, image receiving sheets were obtained in the same manner as in Example 1, except that the synthetic papers obtained in Examples 2 to 4 were used.

(Left below) An emulsion obtained by emulsion polymerization of the monomers shown in Table 2 as a coating agent is used as the component (2), and (A) and (B
A receptor sheet was prepared by coating and drying on high-quality paper in the same manner as in Example 1, except that the mixing ratio of components J and C) was changed as shown in Table 2.

These thermal transfer image-receiving sheets were evaluated by the following method.

The results are shown in Table 2.

Image judgment method: (1) Image receiving sheets prepared in each example and comparative example and sublimable dye (trade name, Kayaset B 1uee 1)
36゜ Nippon Kayakusho) coated and dried transfer paper is layered,
An image is obtained by heating at 120° C. for 5 seconds.

(2) The degree of a and white areas of the obtained images were evaluated on the following five scales.

Evaluation criteria 5: Very good 4 Good 3 No practical problems 2 Practical problems 1 Bad (3) The adhesion test piece was fixed horizontally, and the adhesion tape was crimped on it.
A load of 500 grams is dropped from a height of 8 inches, and when the tip of the adhesive tape is pulled and peeled off at an angle of 45 degrees, a case where the receptive layer does not peel off from the support is considered good (○), and a case where it peels off is judged as good. (x).

Blocking resistance test: Put the front and back sides of a 30α x 30m sample together at a temperature of 40°C.
The head was left for 24 hours under a load of 500 y in an atmosphere with a humidity of 60 degrees.

Judgment was made based on the following criteria according to JISK-6833.

× Blocking to the extent that damage is observed on the surface.

Δ　Blocking to the extent that no damage is observed on the surface.

○ The sample is easily peeled off.

TP (Glass transition point): The glass transition temperature of the copolymer was calculated from the homopolymer glass transition temperature using the following formula.

However, Ty: glass transition temperature (absolute temperature) of the copolymer W, ,
W2. W3...: Weight % of a specific monomer in the copolymer composition T, , T2. T3...: Glass transition temperature of the homopolymer made of that monomer (Absolute temperature) The following values were used for the T of each homopolymer.

Methyl methacrylate 120°C 2-ethylhexyl acrylate) -74°C Dimethylaminoethyl methacrylate 18°C (blank space below) - Draw a line segment 16.16' of 4wm perpendicular to the long axis (tl) of the protrusion, centering on b.
On this line 16.16', use a continuous thickness gauge EL made by Anritsu Denki.
ECTRONIC MICROMETERK-306A (
(product name), draw four line segments 16', 16'' parallel to the major axis t, centering on points 16-c, 16-d 16.16' apart from this line, and draw this line. Measure the top of the line segment 16", 16# with the above thickness gauge, find the highest points 17', 17" of the line segment 16#, 16#, and find the 17.17', 17
Select three points in order of height higher than ", 17", and set the plane containing these three points as the flat surface 18 (in Fig. 5, 17.17', 1
7′).

16.16', 16", 16
Vertex measured above (17, 17', 17'', 17'')
If the difference between the lowest points measured on the same line is 10 μm or more, the line segments 16-a, 16-b, 16-C11 are newly added.
New center points 16-a, 16-b, 16 near 6-d
-c or 16-d is provided and the flat surface 18 is obtained by the same procedure.

[Brief explanation of drawings]

FIG. 1 is a plan view of a transfer thermosensitive recording device, FIG. 2 is a sectional view of the support, FIG. 3 is a partial sectional view of the support, and FIG. 4 is a partial sectional view of the support without a surface layer. FIG. 5 is a partial perspective view showing a method for determining a flat surface. In the figure, 1 is an image-receiving sheet for thermal transfer recording, 11 is an image-receiving layer, 12 is a support, 2 is a transfer body, and 14 is a protrusion. A is a base material layer, B is a paper-like layer, and C is a surface layer. Special applicant: Oji Yuka Synthetic Paper Co., Ltd. Special applicant: Chuo Rika Kogyo Co., Ltd. Agent Patent attorney: Furukawa
Keito Hide Toshiyo Patent Attorney Masahisa Hase Figure 1 Figure 2 Figure 3 □--1m21 Figure 5

Claims (1)

[Claims] 1) A synthetic paper made of a polyolefin film with a whiteness of 90% or more is used as a support, and 0.5% or more is applied to the surface of this support.
In an image-receiving sheet for thermal transfer recording provided with an image-receiving layer having a wall thickness of ~20 microns, the image-receiving layer comprises (A) a cationic acrylic copolymer aqueous emulsion (B) two or more molecules in one molecule. Amino compound having an amino group (C) Epoxy compound Containing the above components (A), (B) and (C), (A)
Component (B) is 1 part by weight per 100 parts by weight of the resin solid content of the component.
-20 parts by weight and component (C) in a proportion of 2 to 50 parts by weight of a resin composition, which is coated on a support and dried. sheet. 2) The cationic acrylic copolymer aqueous emulsion of component (A) contains 0.5 to 10 mol% of the cationic monomer represented by the general formula (a) or (b) and other vinyl monomers. It is an emulsion obtained by emulsion polymerization of 99.5 to 90 mol% of copolymer, and the glass transition point of this copolymer is -10°C to
The image-receiving sheet for thermal transfer recording according to claim 1, characterized in that it is heated to +80°C. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(a) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(b) [In the formula, R^1 is H or CH_3, and R^2 is a carbon number of 2 to 4. It is an alkylene group, and R^3 and R^4 are H
Or it is an alkyl group having 1 to 4 carbon atoms. 3) The amino compound of component (B) is a compound selected from polyalkylene polyamine, polyethyleneimine, and a modified polyamine obtained by reacting a polyamine with an epoxy compound. 2. The image-receiving sheet for thermal transfer recording according to item 1. 4) The thermal transfer according to claim 1, wherein the surface of the support in contact with the image-receiving layer has a smoothness of 3,000 seconds or more according to the Beck index measured according to JISP-8119. Image receiving sheet for recording. 5) The synthetic paper of the support is a synthetic paper with a multilayer structure, and the paper-like layer is a polyolefin film containing 8 to 65 wt% of inorganic fine powder, and the surface thereof is free of inorganic fine powder or has an average particle size. Synthetic paper with a surface layer comprising a polyolefin film containing 3% or less of inorganic fine powder with a diameter of 1 micron or less, in which the major diameter of the protrusions protruding from the flat surface of the surface layer is 50 microns or more. 0 things
．． The image-receiving sheet for thermal transfer recording according to claim 1, characterized in that the number of such sheets is 10 or less per 1 m^2. 6) The image-receiving sheet for thermal transfer recording according to claim 5, which is an oriented film obtained by simultaneously stretching the paper-like layer and the surface layer in a uniaxial direction. 7) Thermal transfer according to claim 5, wherein the paper-like layer is a polyolefin film having a large number of fine voids inside and on the surface of which inorganic fine powder protrudes from the polyolefin resin surface. Image receiving sheet for recording. 8) The image-receiving sheet for thermal transfer recording according to claim 5, wherein the surface layer of the support has a wall thickness of 3 to 15 microns. 9) The image-receiving sheet for thermal transfer recording according to claim 1, wherein the polyolefin is polypropylene.